Mitigation of cascading failures by selective inter-subnetwork power shifts under multi-objective decision making

The paper presents a framework for alleviating line overloads and mitigating consequences of cascading events. For a network in emergency conditions due to single or multiple line overloads, graph-partitioning algorithm is developed to identify subnetworks for which the overloaded lines acts as “power gates”. The alleviation of overloaded lines, which bridge the identified subnetworks, is achieved by inter-subnetwork power shifts through generation rescheduling and, possibly, load shedding. A multi-objective decision making method is adopted for the power shifts selection based on the sensitivities of power shifts to the overloaded lines. The framework has been tested on the IEEE RTS-96 system to illustrate its capability in cascading outages mitigation and load shedding reduction.